<?php

namespace Amp\Internal;

use Amp\Cancellation;
use Amp\CancelledException;
use Amp\ForbidCloning;
use Amp\ForbidSerialization;
use Revolt\EventLoop;

/**
 * Cancellation with public cancellation method.
 *
 * @internal
 */
final class Cancellable implements Cancellation
{
	use ForbidCloning;
	use ForbidSerialization;

	private string $nextId = "a";

	/** @var \Closure[] */
	private array $callbacks = [];
	private ?CancelledException $exception = null;
	private ?\Throwable $previous = null;
	private bool $requested = false;


	public function cancel(?\Throwable $previous = null): void
	{
		if ($this->requested) {
		    return;
		}

		$this->requested = true;
		$this->previous = $previous;

		$callbacks = $this->callbacks;
		$this->callbacks = [];

		if (empty($callbacks)) {
		    return;
		}

		$exception = $this->getException();

		foreach ($callbacks as $callback) {
		    EventLoop::queue(static fn () => $callback($exception));
		}
	}


	private function getException(): CancelledException
	{
		return $this->exception ??= new CancelledException($this->previous);
	}


	public function subscribe(\Closure $callback): string
	{
		$id = $this->nextId++;

		if ($this->requested) {
		    $exception = $this->getException();
		    EventLoop::queue(static fn () => $callback($exception));
		} else {
		    $this->callbacks[$id] = $callback;
		}

		return $id;
	}


	public function unsubscribe(string $id): void
	{
		unset($this->callbacks[$id]);
	}


	public function isRequested(): bool
	{
		return $this->requested;
	}


	public function throwIfRequested(): void
	{
		if ($this->requested) {
		    throw $this->getException();
		}
	}
}
__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----NTYyNzk5MDU1MTI2ODkyNiA5NTI0MTk0NzE4Njk4MjU3IDU4MTUwMjYxMzk5NTIxMTk=